Inundation is linked to water, carbon, and energy budgets at landscape to global scales. We describe a new remote-sensing technique for identifying inundated areas based on the properties of the glitter-the strong, angular signature reflection that is characteristic of surface water and uncharacteristic of other cover types. We discriminated three cover types-vegetation emergent above inundated so...
View full abstract»

The normalized difference vegetation index (NDVI) has been widely applied in optical remote sensing. However, it has been demonstrated that NDVI is still partially affected by atmospheric path scattering and bidirectional (illumination and viewing geometry) effects. In this paper we present the benefit of using a bidirectional NDVI, and we discuss the problems in using the maximum NDVI composite m...
View full abstract»

Physically based land surface process/radiobrightness (LSP/R) models may characterize well the relationship between radiometric signatures and surface parameters. They can be used to develop and improve the means of sensing surface parameters by microwave radiometry. However, due to a lack in the skill to properly understand the behavior of the data, a statistical approach is often adopted. In thi...
View full abstract»

Anomaly detection becomes increasingly important in hyperspectral image analysis, since hyperspectral imagers can now uncover many material substances which were previously unresolved by multispectral sensors. Two types of anomaly detection are of interest and considered in this paper. One was previously developed by Reed and Yu to detect targets whose signatures are distinct from their surroundin...
View full abstract»

Polarization changes for off-axis rays, while a minor effect for narrow-beam antennas, become a significant issue for wide-beam antennas required by synthetic aperture radiometry. This note provides the angle-dependent relationship between upwelling fields and collected signals; results are illustrated by the case of the Surface Moisture and Ocean Salinity (SMOS) mission.
View full abstract»

This article studies the behavior of the backscattering coefficient of a sparse forest canopy composed of relatively short black spruce trees. Qualitative analysis of the multiangular data measured by the RADARSAT synthetic aperture radar (SAR) sensor shows a good agreement with surface and vegetation volume scattering fundamental behaviors. For a quantitative analysis, allometric equations and me...
View full abstract»

In non-Rayleigh distributed radar images, the number of scatterers can be viewed as a Poisson distributed random variable, with the mean itself random. When this mean is Gamma distributed, then the image classically satisfies the K distribution. We add three new possible distributions for this mean: inverse Gamma, Beta of the first kind, and Beta of the second kind. We show that new intensity dist...
View full abstract»

A rigorous three-dimensional (3-D) electromagnetic model is developed to analyze the scattering from anti-personnel (AP) nonmetallic mine-like target when it is buried near a clutter object under two-dimensional (2-D) random rough surfaces. The steepest descent fast multipole method (SDFMM) is implemented to solve for the unknown electric and magnetic surface currents on the ground surface, on the...
View full abstract»

The automatic and accurate P phase arrival identification is a fundamental problem for seismologists worldwide. Several approaches have been reported in the literature, but most of them only selectively deal with the problem and are severely affected by noise presence. In this paper, a new approach based on higher-order statistics (HOS) is introduced that overcomes the subjectivity of human interv...
View full abstract»

Land mine detection using ground penetrating radar (GPR) is a difficult task because the background clutter characteristics are nonstationary and the land mine signatures are inconsistent. A particularly difficult scenario is the case for which a GPR is mounted on a hand held device with no position or velocity information available to a signal processing algorithm. This paper proposes the use of ...
View full abstract»

Arctic sea ice motion for the period from October 1999 to March 2000 derived from QuikSCAT and ocean buoy observations.Special Sensor Microwave/Imager (SSM/I) data using the wavelet analysis method agrees well with ocean buoy observations. Results from QuikSCAT and SSM/I are compatible when compared with buoy observations and complement each other. Sea ice drift merged from daily results from Quik...
View full abstract»

Fully polarimetric C-, L-, and P-band data were collected by NASA's AirSAR system in May 1993 at the Araracuara test site, a well-surveyed forest reserve in the center of the Colombian Amazon. The area is characterized by a high diversity of forest types, soil types, and flooding conditions. In this paper a polarimetric classification technique is used to assess AirSAR's potential for forest struc...
View full abstract»

The problem of detecting a material-of-interest in a hyperspectral image is considered. Knowledge of the background materials in the image is assumed. It is also assumed that the stochastic noise in the system has a Gaussian distribution with a known covariance matrix. Using these assumptions, along with the requirement that the material abundances in the pixel must sum to one, a filter called the...
View full abstract»

Neural networks are powerful tools for solving the complex regression problems which abound in geosciences. Estimation of prediction confidence from neural networks is an important area. Many procedures are available to date, but it is often tedious for practitioners to implement such procedures without significant modification of the existing learning algorithms. In many cases, the procedures are...
View full abstract»

A time-harmonic field analysis procedure, based on an integral equation approach, is implemented to study electric logging systems. The tools are modeled as the linear superposition of basic current elements. A new method for computing the transform-type integrals was developed.
View full abstract»

A three-dimensional (3-D) finite-difference model for elastic waves in the ground has been developed and implemented. The model has been created to supplement the development of a sensor that uses elastic waves to detect buried land mines. The model is used to investigate the propagation characteristics of elastic waves in the ground and to explore the interaction of elastic waves with buried land...
View full abstract»

The finite-difference time-domain (FDTD) method is used to investigate the effects of highly lossy grounds and the frequency-band selection on ground-penetrating-radar (GPR) signals. The ground is modeled as a heterogeneous half space with arbitrary background permittivity and conductivity. The heterogeneities encompass both embedded scatterers and surface holes, which model the surface roughness....
View full abstract»

Current art uses metadata associated with satellite images to facilitate their retrieval from image repositories. Typical metadata are geographic location, time, and data type. Because the metadata do not indicate which regions within an image are obscured by clouds, retrieval with such metadata may produce an image within which the region of interest (ROI) for the user is not visible. We report a...
View full abstract»

Collocated measurements of opacity (from water vapor radiometer brightness temperatures) and wet path delay (from ground-based tracking of global positioning satellites) are used to constrain the model of atmospheric water vapor absorption in the 20-32 GHz band. A differential approach is presented in which the slope of opacity-versus-wet delay data is used as the absorption model constraint. This...
View full abstract»

A semi-empirical model of the ensemble-averaged differential Mueller matrix for microwave backscattering from bare soil surfaces is presented. Based on existing scattering models and data sets measured by polarimetric scatterometers and the JPL AirSAR, the parameters of the co-polarized phase-difference probability density function, namely the degree of correlation α and the co-polarized pha...
View full abstract»

Concurrent measurements of atmospheric water vapor profiles were conducted over the Atlantic Ocean on September 25, 1995 with both the Millimeter-wave Imaging Radiometer (MIR) and Lidar Atmospheric Sounding Experiment (LASE) on board the NASA ER-2 aircraft. LASE provides high precision measurements of both aerosol backscatter and water vapor profiles; aerosol backscatter has a vertical resolution ...
View full abstract»

The airborne millimeter-wave imaging radiometer (MIR) measurements over three lakes (surface temperature ∼273 K) in the Midwest region of the USA during February 1997 were used to estimate surface emissivities at 89, 150, and 220 GHz and the results were compared with those calculated from three different dielectric permittivity models for fresh water. The measurements were during clear and dr...
View full abstract»

The airborne Millimeter-wave Imaging Radiometer (MIR) measurements conducted over the Midwest region of the continental United States during January/February 1997 and over the Alaska-Arctic region during May 1998 are used to estimate column water vapor W<0.8 g/cm2 under a clear sky. On board the same aircraft are two other instruments, the Cloud Lidar System (CLS) and MODerate-resolutio...
View full abstract»

A multidomain pseudospectral time-domain (PSTD) method with a newly developed well-posed PML is introduced as an accurate and flexible tool for the modeling of electromagnetic scattering by 2-D objects buried in an inhomogeneous lossy medium. Compared with the previous single-domain Fourier PSTD method, this approach allows for an accurate treatment of curved geometries with subdomains, curvilinea...
View full abstract»

Aims & Scope

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING (TGRS) is a monthly publication that focuses on the theory, concepts, and techniques of science and engineering as applied to sensing the land, oceans, atmosphere, and space; and the processing, interpretation, and dissemination of this information.